1. Field of the Invention
The present invention relates to an air passageway opening/closing device for opening/closing two adjacent air passageways by a door means and is suitable for use for an automotive air-conditioning system.
2. Description of the Related Art
Conventionally, an air passageway opening/closing device in an automotive air-conditioning system was structured using a rotary door, integral with a shaft, comprised of a plate door rotatable about the shaft or a door surface comprised of an arc shape or flat shape at a position a predetermined distance from the shaft outward in the radial direction so as to open/close the air passageways by a rotational operation of the door around the shaft.
However, in this related art, it is necessary to provide space for the rotational operation of the door inside a casing of the air-conditioning system. Therefore, the size of the air-conditioning system inevitably becomes larger.
In the past, in this regard, a structure moving flat sliding door in a direction intersecting the flow of air of an air passageway so as to open/close the air passageway has been known.
With this flat sliding door, the door moves along an end face of an opening of the air passageway in a direction intersecting the air flow, therefore space for rotational operation of the door becomes unnecessary and the air-conditioning system can be made smaller in size.
However, when using this flat sliding door to simultaneously open two adjacent air passageways, the flat sliding door is inevitably operated to a position close to the center of the two adjacent air passageways to thereby form openings of the two adjacent air passageways at both the front and rear of the direction of movement of the sliding door.
As a result, the air in the casing of the air-conditioning system flows to the two air passageways split largely by the length of the sliding door at the sides at the front and rear-of the direction of movement of the door. For this reason, in an air mix type air-conditioning system or other such system adjusting the temperature of the air blown into the cabin according to the ratio of the amount of the cool air and warm air, the phenomenon arises that the cool air mainly flows to one of the two air passageways, while the warm air mainly flows to the other side of the two air passageways (phenomenon of separation of cool air and warm air), so control of the temperature of the air blown from the two air passageways becomes difficult.
Related art for solving this inconvenience are proposed in U.S. Pat. No. 5,663,630 and U.S. Pat. No. 6,669,549. U.S. Pat. No. 5,653,630 uses a film door constructed by a plastic film member having flexibility. An opening for opening an air passageway is arranged at an intermediate portion in the direction of door movement in the film member forming the film door. The film parts at the front and rear sides of this opening closes the air passageway.
The two ends of the film door in the direction of movement are connected to takeup shafts. By turning the two takeup shafts to tandem, the opening and the film parts of the film door are moved in a direction intersecting the flow of air to open and close the air passageway.
According to U.S. Pat. No. 5,653,630, when simultaneously opening two adjacent air passageways, the opening at the intermediate position of the film door is aligned with the openings of the two air passageways. Therefore, the air in the casing passes through the opening of this film door and flows into the two air passageways. For this reason, the phenomenon of separation of the cool air and warm air does not occur, and the temperature controllability of the air is good.
U.S. Pat. No. 6,669,549 uses a flexible sliding door comprised of a frame shaped part forming an opening for opening an air passageway arranged at an intermediate position in the direction of door movement and flexible film members for closing the air passageway arranged at the two front and rear sides of this frame shaped part.
In this flexible sliding door, the air passageway is opened/closed by connecting a door operating mechanism to the frame shaped part, imparting a door operating force to the frame shaped part, and moving the frame shaped part and the flexible film members in a direction intersecting the flow of air.
In U.S. Pat. No. 6,669,549, the air can be sent into two air passageways through the opening of the frame shaped part in the same way as U.S. Pat. No. 5,653,630, therefore the temperature controllability of the air is good in the same way as in U.S. Pat. No. 5,653,630.
However, in U.S. Pat. No. 5,653,630, the rotation mechanism for the two takeup shafts for taking up and releasing the two ends of the film door in the movement direction is complex, therefore there is the problem that production costs become high.
Also, in U.S. Pat. No. 6,669,549, since flexible film members having large enough sizes to fully close the opening of the air passageway are arranged at the two front and rear sides of the frame shaped part, it is necessary to provide enough space for accommodating the front and rear side flexible film members in the casing of the air-conditioning system. The provision of this space enlarges the size of the air-conditioning system.